yosys/tests/techmap/breaksop.ys

log -header "Simple positive case"
log -push
design -reset
read_verilog <<EOF
module top (
  input wire [2:0] a,
  output wire x
);
  assign x = a[0] | (a[1] & a[2]);
endmodule
EOF
check -assert

# Generate $sop
techmap
abc -sop
select -assert-count 1 t:$sop

# Check equivalence after breaksop
equiv_opt -assert breaksop

# Check final design has correct number of gates
design -load postopt
select -assert-count 2 t:$reduce_and
select -assert-count 1 t:$reduce_or

design -reset
log -pop



log -header "With negation"
log -push
design -reset
read_verilog <<EOF
module top (
  input wire [2:0] a,
  output wire x
);
  assign x = ~a[0] | (~a[1] & ~a[2]);
endmodule
EOF
check -assert

# Generate $sop
techmap
abc -sop
select -assert-count 1 t:$sop

# Check equivalence after breaksop
equiv_opt -assert breaksop

# Check final design has correct number of gates
design -load postopt
write_verilog dump_post.v
select -assert-count 2 t:$reduce_and
select -assert-count 1 t:$reduce_or

design -reset
log -pop



log -header "More depth"
log -push
design -reset
read_verilog <<EOF
module top (
  input wire [3:0] a,
  output wire x
);
  assign x = (a[0] & a[1]) | (~a[2] & a[3]) | (a[0] & ~a[1] & a[2]);
endmodule
EOF
check -assert

# Generate $sop
techmap
abc -sop
select -assert-count 1 t:$sop

# Check equivalence after breaksop
equiv_opt -assert breaksop

# Check final design has correct number of gates
design -load postopt
select -assert-count 3 t:$reduce_and
select -assert-count 1 t:$reduce_or

design -reset
log -pop



log -header "Only ORs"
log -push
design -reset
read_verilog <<EOF
module top (
  input wire [3:0] a,
  output wire x
);
  assign x = a[0] | a[1] | a[2] | a[3];
endmodule
EOF
check -assert

# Generate $sop
techmap
abc -sop
select -assert-count 1 t:$sop

# Check equivalence after breaksop
equiv_opt -assert breaksop

# Check final design has correct number of gates
# We only have one AND gate since breaksop turns the OR gate into an AND gate
# The inputs to this gate are inverted and the outputs are also inverted, so with 
# DeMorgan's law, they are equivalent
design -load postopt
opt     # Run opt to remove unneeded OR gate
select -assert-count 1 t:$reduce_and
select -assert-count 0 t:$reduce_or

design -reset
log -pop



log -header "With constants"
log -push
design -reset
read_verilog <<EOF
module top (
  input wire [3:0] a,
  output wire x
);
  assign x = (~a[0] & 1'b1) | (a[1] & 1'b0) | (a[2] & a[3]);
endmodule
EOF
check -assert

# Generate $sop
techmap
abc -sop
select -assert-count 1 t:$sop

# Check equivalence after breaksop
write_verilog dump_pre.v
equiv_opt -assert breaksop

# Check final design has correct number of gates
design -load postopt
opt
write_verilog dump_post.v
select -assert-count 2 t:$reduce_and
select -assert-count 1 t:$reduce_or

design -reset
log -pop



log -header "Multiple sops"
log -push
design -reset
read_verilog <<EOF
module top (
  input wire [3:0] a,
  input wire [3:0] b,
  output wire x,
  output wire y
);
  assign x = (a[0] & a[1]) | (~a[2] & a[3]) | (a[0] & ~a[1] & a[2]);
  assign y = (b[0] & b[1]) | (~b[2] & b[3]) | (b[0] & ~b[1] & b[2]);
endmodule
EOF
check -assert

# Generate $sop
techmap
abc -sop
select -assert-count 2 t:$sop

# Check equivalence after breaksop
equiv_opt -assert breaksop

# Check final design has correct number of gates
design -load postopt
select -assert-count 6 t:$reduce_and
select -assert-count 2 t:$reduce_or

design -reset
log -pop